Semiconductor devices are commonly utilized for data storage and processing. The data storage may utilize an array of memory devices. Some memory devices are particularly well-suited for long-term storage of data, while others are better suited for rapid reading and writing (in other words, rapid access). Among the memory devices that are particularly well-suited for rapid access are dynamic random access memory (DRAM) devices. A DRAM unit cell may include a transistor in combination with a capacitor.
A continuing goal of semiconductor fabrication is to reduce the amount of semiconductor real estate consumed by various components to thereby increase integration. It is, however, difficult to reduce the amount of semiconductor real estate consumed by a capacitor while still maintaining desired levels of capacitance. Some methods for reducing the amount of real estate consumed by capacitors, while maintaining desired levels of capacitance, include forming the capacitors to be increasingly thinner and taller.
A capacitor may be formed by patterning an opening in a template material, filling the opening with storage node material, and then removing the template material to leave a capacitor storage node comprising the storage node material. The capacitor storage node may be shaped as a pillar projecting upwardly from a semiconductor substrate. Subsequently, capacitor dielectric material may be formed across the pillar, and capacitor plate material may be formed across the capacitor dielectric material. The capacitor plate material, capacitor dielectric material, and storage node may together form a capacitor.
Difficulties occur as capacitors become thinner and taller in that it becomes increasingly difficult to pattern openings in a template material, and increasingly difficult to fill the openings with capacitor storage node material. Additionally, there is increasing risk that the tall, thin capacitor storage nodes will tip, and possibly topple, before the capacitor dielectric material and capacitor plate material can be formed to provide support to the tall, thin capacitor storage nodes.
It is desired to develop improved methods for forming tall, thin capacitors; and to develop improved capacitor constructions.